KR101919991B1 - Adhesive composition and polarizing plate using the same - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an adhesive composition and a polarizing plate comprising the same, and more particularly to a polyallylamine-based resin having a specific repeating unit; an amine-based resin having a pH of 7.5 to 9 and being water-soluble and cationic; And the crosslinking agent, it is easy to bond with the polarizer regardless of the kind of the polarizer protective film and whether or not the surface treatment is performed, and it is excellent in adhesion and water resistance (color separation of the polarizer) with the polarizer and the polarizer protective film under high temperature and high humidity conditions. To an adhesive composition which can improve durability and reliability in peel strength on the adhesive layer side, and a polarizing plate comprising the adhesive composition.

Description

ADHESIVE COMPOSITION AND POLARIZING PLATE USING THE SAME [0002]

The present invention relates to an adhesive composition and a polarizer in which a polarizer and a polarizer protective film are bonded using the adhesive composition.

The polarizing plate has a structure in which a transparent protective film is laminated on both sides or one side of a polarizer made of a polyvinyl alcohol-based resin in which dichroic dye is adsorbed and oriented.

The polarizer is produced by subjecting a polyvinyl alcohol-based resin film to longitudinal uniaxial stretching and dyeing with a dichroic dye, followed by boric acid treatment to carry out a crosslinking reaction, washing with water and drying. Iodine or a dichroic organic dye is used as the dichroic dye. A polarizer protective film is laminated on both sides or one side of the thus-prepared polarizer to produce a polarizer, which is then used in a liquid crystal display device.

Although the cellulose-based film is widely used as the polarizer-protective film, the cellulose-based film has a drawback that the polarizing plate performance deteriorates due to low humidity and heat resistance, and the protective film and the polarizer are peeled off. Thus, at least one of the polarizer- There have been attempts to construct various resins (acrylic and propylene resins).

Such a polarizer protective film is bonded to a polarizer by an adhesive, and it is disadvantageous to perform a suitable surface treatment process depending on the kind of the protective film or to apply the adhesive selectively.

It is an object of the present invention to provide an adhesive composition which is easy to be bonded to a polarizer irrespective of the kind of polarizer protective film and whether or not the surface treatment is performed.

In order to achieve the above object, the present invention provides a polyallylamine-based resin having a repeating unit represented by the following formula (1): an amine-based resin having a pH of 7.5 to 9 and being water-soluble and cationic; And a crosslinking agent.

The polyallylamine-based resin may have a weight average molecular weight of 1,000 to 70,000.

The polyallylamine-based resin may be a homopolymer.

The main chain of the amine-based resin may be N, N'-bis (2-aminoethyl) -1,2-ethanediamine.

The amine resin may be one obtained by further copolymerizing one or more compounds selected from the group consisting of epoxy, amino and isobenzofuran dione.

The crosslinking agent may be at least one selected from the group consisting of isocyanate-based, epoxy-based, peroxide-based, metal chelating-based, oxazoline-based, melamine-based, glyoxylate-based and aziridine-based ones.

The adhesive composition may further comprise at least one additive selected from the group consisting of a water-soluble aziridine compound, a plasticizer, a silane coupling agent, an antistatic agent, a fine particle, an alcohol and a leveling agent.

5 to 50 parts by weight of a water-soluble and cationic amine-based resin having a pH of 7.5 to 9 and 100 parts by weight of a polyallylamine-based resin having a repeating unit represented by the formula (1); And 1 to 20 parts by weight of the crosslinking agent.

Further, the present invention provides a polarizing element comprising: a polarizer; An adhesive layer stacked on one surface or both surfaces of the polarizer, the adhesive layer containing the adhesive composition; And a polarizer protective film laminated on the adhesive layer.

The 180 ° peeling force (peeling rate: 300 mm / min) at the adhesive layer surface when peeling the polyvinyl alcohol polarizer may be 0.6 N or more.

Preferably, the 180 占 peeling force (peeling speed 300mm / min) may be 1.0N or more.

The adhesive composition of the present invention is easy to bond with a polarizer irrespective of the kind of the polarizer protective film and whether or not the surface treatment of the polarizer protective film is performed.

In particular, it can be easily used when an anti-adhesion protective film (an uncured cellulosic film, an acrylic film, a propylene-based film, or the like) which is difficult to be bonded with an aqueous adhesive for a polarizing plate.

In addition, the adhesive composition of the present invention is excellent in adhesive force while maintaining optical characteristics equal to or more than conventional, and has excellent adhesive strength and water resistance (color separation phenomenon of a polarizer) to a polarizer and a polarizer protective film under high temperature and high humidity conditions, Can be improved.

In addition, the adhesive composition of the present invention has an advantage of being excellent in the peeling force on the adhesive layer surface when the polarizer is peeled from the protective film, thereby reducing the occurrence of defective rate due to the incorporation of bubbles in the durability test.

1 shows a water resistance test method of a polarizing plate.

The present invention relates to an adhesive composition and a polarizer in which a polarizer and a polarizer protective film are bonded using the adhesive composition.

Hereinafter, the present invention will be described in detail.

The pressure-sensitive adhesive composition of the present invention comprises: a polyallylamine-based resin having a repeating unit represented by the following formula (1); an amine-based resin having a pH of 7.5 to 9 and being water-soluble and cationic; And a cross-linking agent.

[Chemical Formula 1]

The adhesive composition of the present invention is not limited to the use of the polarizer and the polarizer protective film, and if the adherend is composed of the components of the polarizer commonly used in the art and the polarizer protective film, Bonding is possible. However, in order to make the explanation more efficient, the polarizer and the polarizer protective film are specified and described in the specification as a whole.

The polyallylamine-based resin of the present invention has a repeating unit represented by the following formula (1), and a homopolymer or a copolymer can be used, but a homopolymer is preferable considering physical properties such as adhesion and durability.

The polyallylamine resin preferably has a weight average molecular weight of 1,000 to 70,000 in order to improve the adhesiveness. When the weight average molecular weight is less than 1,000, it is difficult to obtain the desired adhesive force. When the weight average molecular weight is more than 70,000, bubbles may be incorporated during the bonding process of the polarizer and the protective film.

The amine-based resin serves to improve the adhesion (adhesion) between the polyallylamine-based resin and the polarizer and the polarizer protective film. The amine-based resin is cationic and has a pH of 7.5 to 9. Further, it is water-soluble in consideration of miscibility with the polyvinyl alcohol-based resin.

When an anionic resin is used, the adhesion (adhesion) between the polarizer and the polarizer protective film may be lowered. If the pH is less than 7.5, the water resistance may deteriorate. If the pH is more than 9, the adhesion (adhesion) may be deteriorated.

The amine-based resin may be a resin containing N, N'-bis (2-aminoethyl) -1,2-ethanediamine as a main chain, and may be selected from epoxy resins, amino resins, and isobenzofuran dione resins. It is possible to more advantageously use the above-mentioned copolymer in which more than one kind of compound is copolymerized to achieve the effect of the present invention.

Commercially available products may be Sumirez Resin SPI-203 (50) H manufactured by Taoka Chemical Co., and Sumirez Resin SPI-106N manufactured by Taoka Chemical.

Such an amine resin is contained in an amount of 5 to 50 parts by weight, preferably 10 to 25 parts by weight, based on 100 parts by weight of the polyallylamine resin (based on the solid content). When the content is less than 5 parts by weight, the adhesive strength may be lowered. When the content is more than 50 parts by weight, the viscosity may be high and the processability may be deteriorated.

The crosslinking agent serves to improve the adhesion and durability of the polyallylamine-based resin, the polarizer and the polarizer protective film, the reliability at high temperature, and the shape of the pressure-sensitive adhesive.

The cross-linking agent may be an isocyanate-based, epoxy-based, peroxide-based, metal chelating-based, oxazoline-based, melamine-based, glyoxylate-based or aziridine-based one or a mixture of two or more thereof.

A glyoxylate which is advantageous in terms of double stickiness and durability is preferable.

The present invention specifically describes the glyoxylate crosslinking agent, which is a preferable crosslinking agent component in the following, but is not limited thereto.

The glyoxylate may be an alkali metal salt or an alkaline earth metal salt of glyoxylic acid. The alkali metal salt and the alkaline earth metal salt of the above-mentioned glyoxylic acid can obtain substantially the same effect, and there is no particular limitation on their use. This is presumably because both the alkali metal and the alkaline earth metal are low in electronegativity and the carboxylic acid salt of the metal or the earth metal is similar in chemical properties. In addition, since the portion acting as a crosslinking agent is an aldehyde group of the glyoxylate, it is predicted that the metal or the metal will exhibit the same effect.

Examples of the glyoxylate include alkali metal salts such as lithium glyoxylate, sodium glyoxylate and potassium glyoxylate, alkaline earth metal salts such as magnesium glyoxylate, calcium glyoxylate, strontium glyoxylate and barium glyoxylate, Can be used. In consideration of the solubility in water, an alkali metal salt is preferable, and sodium glyoxylate is particularly preferable.

Such a crosslinking agent is contained in an amount of 1 to 20 parts by weight, preferably 5 to 10 parts by weight based on 100 parts by weight of the polyallylamine resin (based on the solid content). If the content is less than 1 part by weight, the water resistance of the polarizing plate may not be sufficiently exhibited. If the content is more than 20 parts by weight, the optical characteristics (transmittance, polarization degree) of the polarizing plate may be lowered.

The adhesive composition may be used in an amount of at least one selected from the group consisting of a plasticizer, a silane coupling agent, an antistatic agent, a fine particle, an alcohol, and a leveling agent, which are generally used in the art within the range not hindering the desired effect have. In particular, in order to improve the spreadability of the composition for forming an adhesive layer, it is preferable to use an alcohol, a leveling agent or the like.

It is preferable that the adhesive composition is in a liquid form in order to form a uniform adhesive layer on the surface of the polarizer or the protective film as the adhesive. A solution type or a dispersed liquid type of various solvents can be used for such a liquid type adhesive, and a solution type is preferable in view of the coated surface of the substrate, and a solution type or a dispersed liquid type in which water is used as a solvent is suitable from the viewpoint of stability.

For the purpose of shortening the drying process, a water / alcohol mixed solvent in which an alcoholic solvent having a boiling point lower than that of water is easily mixed with water in an adhesive solution may be used. The boiling point of the alcoholic solvent is preferably 100 占 폚 or lower, particularly 80 占 폚 or lower, or 70 占 폚 or lower.

The present invention provides a polarizer comprising: a polarizer; An adhesive layer stacked on one surface or both surfaces of the polarizer, the adhesive layer containing the adhesive composition; And a polarizer protective film laminated on the adhesive layer.

A polarizer is one in which a dichroic dye is adsorbed and oriented on a stretched polyvinyl alcohol film.

The polyvinyl alcohol-based resin constituting the polarizer can be obtained by saponifying a polyvinyl acetate-based resin. Examples of the polyvinyl acetate resin include polyvinyl acetate, which is a homopolymer of vinyl acetate, and copolymers of vinyl acetate and other monomers copolymerizable therewith. Other monomers copolymerizable with vinyl acetate include acrylamide monomers having an unsaturated carboxylic acid type, an unsaturated sulfonic acid type, an olefin type, a vinyl ether type, and an ammonium group. The polyvinyl alcohol resin may also be modified. For example, polyvinyl formal or polyvinyl acetal modified with aldehydes may be used. The saponification degree of the polyvinyl alcohol-based resin is usually 85 to 100 mol%, preferably 98 mol% or more. The degree of polymerization of the polyvinyl alcohol-based resin is usually 1,000 to 10,000, preferably 1,500 to 5,000.

Such a polyvinyl alcohol-based resin film is used as the original film of the polarizer. The method of forming the film of the polyvinyl alcohol-based resin is not particularly limited, and a known method can be used. The thickness of the original film is not particularly limited, and may be, for example, 10 to 150 mu m.

The polarizer of the present invention is produced by continuously uniaxially stretching a polyvinyl alcohol-based film in an aqueous solution, staining with a dichroic dye and adsorbing, treating with an aqueous solution of boric acid, and washing and drying.

The uniaxial stretching of the polyvinyl alcohol film may be performed before dyeing, concurrently with dyeing, or may be performed after dyeing. If uniaxial stretching is carried out after dyeing, it may be carried out before the boric acid treatment, or may be carried out during the boric acid treatment. Of course, it is also possible to perform uniaxial stretching in a plurality of such steps. For uniaxial stretching, other rolls or rolls of different circumferences may be used. The uniaxial stretching may be either dry stretching in air or wet stretching in the state of being swollen with a solvent. The stretching ratio is usually 4 to 8 times.

As a step of dyeing a stretched polyvinyl alcohol film with a dichroic dye, for example, a method of immersing a polyvinyl alcohol film in an aqueous solution containing a dichroic dye can be used. As the dichroic dye, iodine or a dichroic dye is used. It is preferable that the polyvinyl alcohol film is pre-immersed in water before dyeing to swell.

When iodine is used as the dichroic dye, a method in which a polyvinyl alcohol-based film is dipped in an aqueous solution for dyeing usually containing iodine and potassium iodide may be used. Usually, the content of iodine in an aqueous solution for dyeing is 0.01 to 1 part by weight with respect to 100 parts by weight of water (distilled water), and the content of potassium iodide is 0.5 to 20 parts by weight with respect to 100 parts by weight of water. The temperature of the aqueous solution for dyeing is usually 20 to 40 占 폚, and the immersion time (dyeing time) is usually 20 to 1,800 seconds.

When a dichroic dye is used as the dichroic dye, a method of dying and dyeing a polyvinyl alcohol-based resin film in an aqueous solution containing a water-soluble dichroic dye is generally employed. The content of the dichroic dye in this aqueous solution is usually 1 × 10 ^-4 to 10 parts by weight, preferably 1 × 10 ^-3 to 1 part by weight, per 100 parts by weight of water. The aqueous solution may contain an inorganic salt such as sodium sulfate as a dyeing aid. The dye aqueous solution used for dyeing usually has a temperature of 20 to 80 DEG C, and the immersion time for this aqueous solution is usually 10 to 1,800 seconds.

The step of treating the dyed polyvinyl alcohol film with boric acid can be carried out by immersing it in an aqueous solution containing boric acid. In general, the boric acid content in the boric acid-containing aqueous solution is preferably 2 to 15 parts by weight, and more preferably 5 to 12 parts by weight based on 100 parts by weight of water. When iodine is used as the dichroic dye, it is preferable that the aqueous solution containing boric acid contains potassium iodide. The content thereof is usually 0.1 to 15 parts by weight, preferably 5 to 12 parts by weight per 100 parts by weight of water. The temperature of the boric acid-containing aqueous solution is usually 50 ° C. or higher, preferably 50 to 85 ° C., and more preferably 60 to 80 ° C. The immersing time is usually 60 to 1,200 seconds, preferably 150 to 600 seconds, Preferably 200 to 400 seconds.

After the boric acid treatment, the polyvinyl alcohol film is usually washed with water and dried. The washing treatment can be carried out by immersing the boric acid-treated polyvinyl alcohol-based film in water. The water temperature of the water treatment is usually 5 to 40 占 폚, and the immersion time is usually 1 to 120 seconds. After washing with water, the polarizer can be obtained. The drying treatment can be usually carried out using a hot air dryer or a far infrared ray heater. The drying treatment temperature is usually 30 to 100 占 폚, preferably 50 to 80 占 폚, and the drying time is usually 60 to 600 seconds, preferably 120 to 600 seconds.

The thickness of the polarizer produced as described above is 5 to 40 탆.

The polarizer protective film is excellent in transparency, mechanical strength, heat stability, moisture shielding property, isotropy and the like, and is not specifically proposed. Specifically, acrylic, cellulose, polyolefin or polyester can be used.

Acrylic resins such as polymethyl (meth) acrylate and polyethyl (meth) acrylate; Polyester resins such as polyethylene terephthalate, polyethylene isophthalate, polyethylene naphthalate and polybutylene terephthalate; Cellulose-based resins such as diacetyl cellulose and triacetyl cellulose; Polyolefin-based resins such as polyethylene, polypropylene, cyclo-based or norbornene structures, and ethylene-propylene copolymers; And the like.

The thickness of the polarizer protective film is preferably 10 to 200 占 퐉, and preferably 10 to 150 占 퐉. Further, when the polarizer protective film is laminated on both sides of the polarizer, the same or different thickness can be maintained.

In the polarizing plate of the present invention, the 180 DEG peel force (peel rate: 300 mm / min) at the adhesive layer surface when the polyvinyl alcohol polarizer is peeled is 0.6 N or more, preferably 1.0 N or more. The peel force is a value at which the adhesive strength can be confirmed. When the peel strength is 0.6 N or more, it means that there is no defect caused by insufficient adhesive force in the durability test.

 The polarizing plate of the present invention is easily bonded to the polarizer irrespective of the kind of the polarizer protective film and the surface treatment treatment.

The surface treatment is carried out in order to facilitate bonding with the polarizer. For example, the surface treatment is carried out by dry treatment such as primer treatment, plasma treatment, corona treatment, chemical treatment such as alkali treatment (saponification treatment) And the like.

In particular, the present invention relates to a protective film (for example, an uncured cellulose-based protective film) on which chemical treatment such as alkali treatment (saponification treatment) is not performed, an acrylic or propylene- The protective film is also easy to bond.

The thickness of the adhesive layer is usually about 0.01 to 10 mu m, preferably 0.05 to 5 mu m, and most preferably 0.1 to 1 mu m. The surface of the protective film not bonded to the polarizer may be subjected to a treatment for hard coat treatment, antireflection treatment, anti-sticking, diffusion or anti-glare treatment.

The bonding method may be a conventional method in the art. For example, the bonding method may be applied to the bonding surface of the polarizer or the protective film using a flexible method, a Meyer bar coating method, a gravure coating method, a die coating method, a dip coating method, A method of applying the adhesive composition, and then bonding them together. The flexographic method is a method in which the polarizer or the protective film is moved in the vertical direction, the horizontal direction, or the inclined direction between the two, while applying the adhesive composition to the joint surface. After applying the adhesive composition, a polarizer or a protective film is put on a nip roll or the like and bonded.

After bonding the polarizer and the protective film, a drying treatment can be carried out. The drying treatment is carried out, for example, by spraying hot air. The drying temperature is suitably selected in the range of 40 to 100 占 폚, preferably 60 to 100 占 폚. The drying time may be about 20 to 1,200 seconds. After drying, it is preferable to cure at a room temperature or a slightly higher temperature, for example, at a temperature of 20 to 50 DEG C for about 12 to 600 hours. The thickness of the adhesive layer after drying is usually 0.001 to 5 mu m, preferably 0.01 to 2 mu m, more preferably 0.01 to 1 mu m or less. If the thickness of the adhesive layer exceeds 5 탆, the problem of appearance defects of the polarizing plate tends to occur.

A surface treatment layer such as a hard coating layer, an antireflection layer, an antiglare layer, and an antistatic layer may be further laminated on the other side of the polarizer to which the polarizer protective film is bonded on one side. Further, an optical functional film may be further laminated by a pressure-sensitive adhesive layer. Examples of the optically functional film include an optical compensation film in which a liquid crystal compound or a polymer compound thereof is oriented on the surface of a base material, an optical compensation film that transmits polarized light of any kind and reflects polarized light of a property opposite to that, A retardation film including a cyclic polyolefin resin, an antireflection functional film having a concavo-convex shape on its surface, an additional film having a surface antireflection treatment, a reflection film having a reflective function on the surface, And a transflective film having both a reflecting function and a transmitting function.

In addition, the present invention can form a liquid crystal display device including the polarizing plate.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the present invention. Such variations and modifications are intended to be within the scope of the appended claims.

Manufacturing example  : Polarizer  Produce

A polyvinyl alcohol film having a thickness of 75 탆 and an average degree of polymerization of 2,400 and a saponification degree of 99.9 mol% or more was uniaxially stretched by a dry method about 5 times and immersed in water (distilled water) at 60 캜 for 1 minute while maintaining the stretched state And immersed for 60 seconds in an aqueous solution at 28 DEG C in which the weight ratio of after-iodine / potassium iodide / distilled water was 0.05 / 5/100. Thereafter, the substrate was immersed in an aqueous 72 ° C aqueous solution having a weight ratio of potassium iodide / boric acid / distilled water of 8.5 / 8.5 / 100 for 300 seconds, washed with distilled water at 26 ° C for 20 seconds and dried at 65 ° C to remove iodine Adsorbed polarizers were prepared.

Example  One

(1) Adhesive composition

(Sumirez Resin SPI-203 (50)) having a pH of 8 and a pH of 8 and having a pH of 8 was added to 100 parts by weight (solids content) of an aqueous solution of polyallylamine resin having a weight average molecular weight of 1,000 (product of Nitto Bosa, PAA- H product, Taoka Chemical Co., Ltd.) and 5 parts by weight of sodium glyoxalate (10 wt% aqueous solution) crosslinking agent were mixed to prepare an adhesive composition. At this time, the respective components were mixed based on the solid content.

(2) Polarizer

The adhesive composition of the above (1) was coated on both sides of the polarizer on which the iodine adsorption orientation of the production example was oriented so as to have a dry film thickness of 0.1 mu m, and then the protective film was bonded using niprol. And then dried in a hot-air dryer at 80 ° C for 5 minutes to prepare a polarizing plate.

The protective film was formed by using a saponified triacetyl cellulose protective film, a corona-treated untreated triacetyl cellulose protective film, a corona-treated acrylic protective film, a corona-treated polyethylene terephthalate-based protective film and a corona- Four polarizing plates were prepared.

Example  2 to 13 and Comparative Example  1 to 6

A polarizing plate was prepared in the same manner as in Example 1 except that the composition of the components was used as shown in Table 1 below.

division
(Parts by weight) Polyallylamine resin Amine-based resin Cross-linking agent additive Kinds
(Weight average molecular weight) content Kinds content Example 1 PAA-01 products
(1,000) 100 Sumirez Resin SPI-203 (50) H 10 Sodium glyoxylate (5) - Example 2 PAA-05 products
(5,000) 100 Sumirez Resin SPI-203 (50) H 10 Sodium glyoxylate (5) - Example 3 PAA-08 products
(8,000) 100 Sumirez Resin SPI-203 (50) H 10 Sodium glyoxylate (5) - Example 4 PAA-15C Products
(15,000) 100 Sumirez Resin SPI-203 (50) H 10 Sodium glyoxylate (5) - Example 5 PAA-25C Products
(25,000) 100 Sumirez Resin SPI-203 (50) H 10 Sodium glyoxylate (5) - Example 6 Products PAA-H-10C
(60,000) 100 Sumirez Resin SPI-203 (50) H 10 Sodium glyoxylate (5) - Example 7 PAA-15C Products
(15,000) 100 Sumirez Resin SPI-106N 10 Sodium glyoxylate (5) - Example 8 PAA-15C Products
(15,000) 100 Sumirez Resin SPI-203 (50) H 10 Aziridine resin (5) - Example 9 PAA-15C Products
(15,000) 100 Sumirez Resin SPI-203 (50) H 10 Epoxy resin (5) - Example 10 PAA-15C Products
(15,000) 100 Sumirez Resin SPI-203 (50) H 10 Melamine resin (5) - Example 11 PAA-15C Products
(15,000) 100 Sumirez Resin SPI-203 (50) H 10 Aziridine resin (5) Na ₂ CO ₃
(5) Example 12 PAA-15C Products
(15,000) 100 Sumirez Resin SPI-203 (50) H 25 Sodium glyoxylate (5) - Example 13 PAA-15C Products
(15,000) 100 Sumirez Resin SPI-203 (50) H 50 Sodium glyoxylate (5) - Comparative Example 1 PAA-15C Products
(15,000) 100 - - Sodium glyoxylate (5) - Comparative Example 2 - - Sumirez Resin SPI-203 (50) H 100 Sodium glyoxylate (5) - Comparative Example 3 Epichlorohydrin-modified methyldiallylamine resin 100 Sumirez Resin SPI-203 (50) H 10 Sodium glyoxylate (5) - Comparative Example 4 PAA-15C Products
(15,000) 100 PAS-J-81 10 Sodium glyoxylate (5) - PAA-01 products, PAA-05 products, PAA-08 products, PAA-15 products, PAA-25 products, PAA-H-10C products:
Sumirez Resin SPI-203 (50) H: pH8, cationic, Taoka Chemical
Sumirez Resin SPI-106N: pH9, cationic, Taoka Chemical
PAS-J-81: pH7, cationic, Nittobo
Melamine resin: MW-30HM product, oxidized chemical company
Epoxy resin: Sumirez resin 650 product, Taoka Chemical Industries
Aziridine resin: CX-100 product, DSM company
Epichlorohydrin-modified methyldiallylamine resin: KCA101L product, Senka Co., Ltd.,

Experimental Example

The physical properties of the polarizer prepared in the above Examples and Comparative Examples were measured by the following methods, and the results are shown in Table 2 below.

1. Adhesion (Cutter Evaluation)

The prepared polarizing plate was allowed to stand at room temperature for 1 hour, and then a cutter blade was inserted between each polarizing plate (between the polarizing plate and the polarizing plate protective film), and the way in which the blade was pushed was evaluated according to the following criteria .

[Assessment Methods]

A: The cutter blade does not enter any film.

○: When pushing the blade, it stops when the blade reaches 1 to 2 mm between at least one of the films.

DELTA: When pushing the blade, it stops when the blade reaches 3 to 5 mm between at least one of the films.

X: When pushing the blade, the blade is easily inserted between at least one of the films.

2. Water Resistance

The prepared polarizing plate was allowed to stand for 24 hours under an environment of 23 ° C and a relative humidity of 55%, and tested for water resistance at room temperature. First, the polarizing plate was cut into a rectangular shape of 5 cm x 2 cm with the absorption axis (stretching direction) of the polarizing plate as the long side to prepare a sample, and the dimension in the long side direction was measured accurately. Here, the sample exhibits uniform color uniformly over the entire surface due to iodine adsorbed on the polarizer. As shown in Fig. 1, (A) shows that the short side of the sample 1 is gripped by the grip portion 5 before immersion in the hot water, (B) Showing a shrunk sample 4 after immersing about 80% in the longitudinal direction in a hot water tank at 60 캜 for 4 hours. When the immersion is completed, the sample (4) is taken out of the water tank to wipe the moisture, and the degree of shrinkage of the polarizer is measured. Specifically, the distance from the end 1a of the protective film at the center of the short side of the sample 1 to the end of the polarizer 4 contracted was measured, and this was taken as the contraction length. 1B, the polarizer 4 positioned at the center of the polarizing plate shrinks due to the immersion of hot water, and a region 2 in which the polarizer 4 is not present between the two protective films is formed. In addition, iodine elutes from the peripheral portion of the polarizer 4 which is in contact with the hot water due to the hot water immersion, and a portion 3 in which the color is missing in the peripheral portion of the sample 1 is generated. The degree of discoloration was measured as the distance from the end of the shrunk polarizer 4 at the center of the short side of the sample 1 to the region where the color unique to the polarizing plate remained, and this was taken as the iodine drop length. The total erosion length X means the total erosion length X from the end 1a of the sample 1 at the center of the short side of the sample 1 to the total length of the sample 1 from the end 1a of the sample 1, This is the distance to the area where the color remains. It can be concluded that the smaller the shrinkage length, the iodine dropout length and the total erosion length (X), the higher the adhesiveness (water resistance at room temperature) in the presence of water.

[Assessment Methods]

?: Total erosion length (X) < 2 mm

?: 2 mm? Total erosion length (X) < 3 mm

?: 3 mm? Total erosion length (X) <5 mm

X: 5 mm? Total erosion length (X)

3. Peel force (N / mm)

The polarizing plate thus prepared was allowed to stand at room temperature for 1 hour and then bonded with a hand roller onto a soda glass using a pressure sensitive adhesive. The autoclave treatment was then carried out under the conditions of a pressure of 2 atm, a temperature of 50 ° C and a time of 20 minutes The bubbles were removed. Soda Glass / Adhesive / Corona-treated Unsulfated Cellulose Film / Polarizer / Corona-treated Unsulfated Cellulose In a film construction, uncoated cellulosic corona-treated film in the soda glass orientation. The 180 ^o peeling force (measuring speed 300 mm / min) on the adhesive layer surface when the polarizer was peeled off was measured using a graph.

division Protective film Adhesion durability Peel force
(N / mm) Example 1 Corona treatment
Unsampled triacetyl cellulose ◎ ○ 1.5 Example 2 Corona treatment
Unsampled triacetyl cellulose ◎ ○ 2.2 Example 3 Corona treatment
Unsampled triacetyl cellulose ◎ ○ 2.3 Example 4 Corona treatment
Unsampled triacetyl cellulose ◎ ◎ 2.8 Example 5 Corona treatment
Unsampled triacetyl cellulose ◎ ◎ 2.8 Example 6 Corona treatment
Unsampled triacetyl cellulose ◎ ◎ 2.7 Example 7 Corona treatment
Unsampled triacetyl cellulose ◎ ◎ 2.4 Example 8 The saponified triacetyl cellulose ◎ ◎ 6.4 Corona treatment
Unsampled triacetyl cellulose ◎ ◎ 2.8 Corona treated acrylic ◎ ◎ 3.5 Corona Treated Polyethylene Terephthalate System ◎ ◎ 2.7 Corona-treated propylene-based ◎ ◎ 2.6 Example 9 Corona treatment
Unsampled triacetyl cellulose ◎ ◎ 3.0 Example 10 Corona treatment
Unsampled triacetyl cellulose ◎ ◎ 2.8 Example 11 Corona treatment
Unsampled triacetyl cellulose ◎ ◎ 3.0 Example 12 Corona treatment
Unsampled triacetyl cellulose ◎ ◎ 1.8 Example 13 Corona treatment
Unsampled triacetyl cellulose ◎ ◎ 2.5 Comparative Example 1 Corona treatment
Unsampled triacetyl cellulose ○ × 1.0 Comparative Example 2 Corona treatment
Unsampled triacetyl cellulose × × 0.1 Comparative Example 3 Corona treatment
Unsampled triacetyl cellulose × × 0.1 Comparative Example 4 Corona treatment
Unsampled triacetyl cellulose ○ × 1.0

As shown in Table 2 above, the adhesive compositions for polarizing plates of Examples 1 to 13 containing specific polyallylamine resins and amine resins according to the present invention can be easily bonded to each other regardless of the kind of the polarizer protective film and the surface treatment can do.

In addition, the adhesive compositions for polarizing plate of Examples 1 to 13 according to the present invention exhibit excellent adhesive strength between the polarizer and the polarizer protective film under high temperature and high humidity conditions, excellent water resistance (polarizing loss of the polarizer) of the polarizing plate, Was superior.

1: sample
1a: end of protective film
2: area where no polarizer exists
3: a portion where the color is missing in the peripheral portion of the sample
4: Polarizer
5:

Claims (11)

A polyallylamine-based resin having a repeating unit represented by the following formula (1); an amine-based resin having a pH of 7.5 to 9 and being water-soluble and cationic; And a crosslinking agent:
[Chemical Formula 1]

The adhesive composition according to claim 1, wherein the polyallylamine resin has a weight average molecular weight of 1,000 to 70,000.
The adhesive composition according to claim 1, wherein the polyallylamine-based resin is a homopolymer.
The adhesive composition according to claim 1, wherein the main chain of the amine resin is N, N'-bis (2-aminoethyl) -1,2-ethanediamine.
[5] The adhesive composition according to claim 4, wherein the amine-based resin is further copolymerized with at least one compound selected from epoxy-based, amino-based, and isobenzofuran dione-based compounds.
The adhesive composition according to claim 1, wherein the crosslinking agent is at least one selected from the group consisting of an isocyanate-based, epoxy-based, peroxide-based, metal chelating-based, oxazoline-based, melamine-based, glyoxylate-based and aziridine-based adhesive.
The adhesive composition according to claim 1, wherein the adhesive composition further comprises at least one additive selected from the group consisting of a water-soluble aziridine compound, a plasticizer, a silane coupling agent, an antistatic agent, fine particles, an alcohol and a leveling agent.
The positive photosensitive composition as claimed in claim 1, which comprises 5 to 50 parts by weight of an amine-based resin having a pH of 7.5 to 9 and a water-soluble and cationic property, based on 100 parts by weight of a polyallylamine- And 1 to 20 parts by weight of the crosslinking agent.
A polarizer;
An adhesive layer laminated on one surface or both surfaces of the polarizer and containing the adhesive composition according to any one of claims 1 to 8; And
And a polarizer protective film laminated on the adhesive layer.
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